CVE-2026-55428 (GCVE-0-2026-55428)

Vulnerability from cvelistv5 – Published: 2026-07-07 23:57 – Updated: 2026-07-08 13:11
VLAI
Title
Coder: Route hijacking through lack of validation of agent-supplied AllowedIPs in tailnet coordinator
Summary
Coder allows organizations to provision remote development environments via Terraform. Prior to versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2, the tailnet coordinator validates that an agent's `Addresses` derive from its authenticated UUID but applies no equivalent check to `AllowedIPs`. The coordinator forwards agent-supplied `AllowedIPs` verbatim to tunnel peers which install them into the WireGuard peer configuration. The fix in versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2 validates each `AllowedIPs` prefix against the authenticating agent's UUID just like `Addresses`. As a workaround, monitor coordinator logs for agents advertising unexpected `AllowedIPs` prefixes.
Severity
8.2 (High)
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N
SSVC
Exploitation: none Automatable: no Technical Impact: total
CISA Coordinator (v2.0.3)
CWE
Assigner
References
Impacted products
Vendor Product Version
coder coder Affected: >= 2.34.0, < 2.34.2
Affected: >= 2.33.0, < 2.33.8
Affected: >= 2.30.0, < 2.32.7
Affected: < 2.29.17
Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-55428",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-08T13:10:59.507766Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-07-08T13:11:08.435Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "coder",
          "vendor": "coder",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 2.34.0, \u003c 2.34.2"
            },
            {
              "status": "affected",
              "version": "\u003e= 2.33.0, \u003c 2.33.8"
            },
            {
              "status": "affected",
              "version": "\u003e= 2.30.0, \u003c 2.32.7"
            },
            {
              "status": "affected",
              "version": "\u003c 2.29.17"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Coder allows organizations to provision remote development environments via Terraform. Prior to versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2, the tailnet coordinator validates that an agent\u0027s `Addresses` derive from its authenticated UUID but applies no equivalent check to `AllowedIPs`. The coordinator forwards agent-supplied `AllowedIPs` verbatim to tunnel peers which install them into the WireGuard peer configuration. The fix in versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2 validates each `AllowedIPs` prefix against the authenticating agent\u0027s UUID just like `Addresses`. As a workaround, monitor coordinator logs for agents advertising unexpected `AllowedIPs` prefixes."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 8.2,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "CHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-285",
              "description": "CWE-285: Improper Authorization",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-863",
              "description": "CWE-863: Incorrect Authorization",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-07T23:57:45.338Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/coder/coder/security/advisories/GHSA-wrq8-fcv5-8hvp",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/coder/coder/security/advisories/GHSA-wrq8-fcv5-8hvp"
        },
        {
          "name": "https://github.com/coder/coder/pull/26144",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/coder/coder/pull/26144"
        },
        {
          "name": "https://github.com/coder/coder/releases/tag/v2.29.17",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/coder/coder/releases/tag/v2.29.17"
        },
        {
          "name": "https://github.com/coder/coder/releases/tag/v2.32.7",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/coder/coder/releases/tag/v2.32.7"
        },
        {
          "name": "https://github.com/coder/coder/releases/tag/v2.33.8",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/coder/coder/releases/tag/v2.33.8"
        },
        {
          "name": "https://github.com/coder/coder/releases/tag/v2.34.2",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/coder/coder/releases/tag/v2.34.2"
        }
      ],
      "source": {
        "advisory": "GHSA-wrq8-fcv5-8hvp",
        "discovery": "UNKNOWN"
      },
      "title": "Coder: Route hijacking through lack of validation of agent-supplied AllowedIPs in tailnet coordinator"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-55428",
    "datePublished": "2026-07-07T23:57:45.338Z",
    "dateReserved": "2026-06-16T21:59:57.016Z",
    "dateUpdated": "2026-07-08T13:11:08.435Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-55428",
      "date": "2026-07-08",
      "epss": "0.00408",
      "percentile": "0.32732"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-55428\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2026-07-08T00:16:33.463\",\"lastModified\":\"2026-07-08T19:44:06.553\",\"vulnStatus\":\"Analyzed\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"Coder allows organizations to provision remote development environments via Terraform. Prior to versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2, the tailnet coordinator validates that an agent\u0027s `Addresses` derive from its authenticated UUID but applies no equivalent check to `AllowedIPs`. The coordinator forwards agent-supplied `AllowedIPs` verbatim to tunnel peers which install them into the WireGuard peer configuration. The fix in versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2 validates each `AllowedIPs` prefix against the authenticating agent\u0027s UUID just like `Addresses`. As a workaround, monitor coordinator logs for agents advertising unexpected `AllowedIPs` prefixes.\"}],\"affected\":[{\"source\":\"security-advisories@github.com\",\"affectedData\":[{\"vendor\":\"coder\",\"product\":\"coder\",\"versions\":[{\"version\":\"\u003e= 2.34.0, \u003c 2.34.2\",\"status\":\"affected\"},{\"version\":\"\u003e= 2.33.0, \u003c 2.33.8\",\"status\":\"affected\"},{\"version\":\"\u003e= 2.30.0, \u003c 2.32.7\",\"status\":\"affected\"},{\"version\":\"\u003c 2.29.17\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N\",\"baseScore\":8.2,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"HIGH\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"CHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"NONE\"},\"exploitabilityScore\":1.8,\"impactScore\":5.8}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2026-07-08T13:10:59.507766Z\",\"id\":\"CVE-2026-55428\",\"options\":[{\"exploitation\":\"none\"},{\"automatable\":\"no\"},{\"technicalImpact\":\"total\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"weaknesses\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-285\"},{\"lang\":\"en\",\"value\":\"CWE-863\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:coder:coder:*:*:*:*:*:go:*:*\",\"versionEndExcluding\":\"2.29.17\",\"matchCriteriaId\":\"F97FAF48-192E-4814-82A5-085C44F1D261\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:coder:coder:*:*:*:*:*:go:*:*\",\"versionStartIncluding\":\"2.30.0\",\"versionEndExcluding\":\"2.32.7\",\"matchCriteriaId\":\"7ABD4A9B-6AE8-47D8-A1B7-91E42EE0481B\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:coder:coder:*:*:*:*:*:go:*:*\",\"versionStartIncluding\":\"2.33.0\",\"versionEndExcluding\":\"2.33.8\",\"matchCriteriaId\":\"F759EEF3-6EAE-475B-85F8-38E7D7B47438\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:coder:coder:*:*:*:*:*:go:*:*\",\"versionStartIncluding\":\"2.34.0\",\"versionEndExcluding\":\"2.34.2\",\"matchCriteriaId\":\"397A02BF-6CF6-40B1-B792-D7CB9D229050\"}]}]}],\"references\":[{\"url\":\"https://github.com/coder/coder/pull/26144\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Issue Tracking\",\"Patch\"]},{\"url\":\"https://github.com/coder/coder/releases/tag/v2.29.17\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Release Notes\"]},{\"url\":\"https://github.com/coder/coder/releases/tag/v2.32.7\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Release Notes\"]},{\"url\":\"https://github.com/coder/coder/releases/tag/v2.33.8\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Release Notes\"]},{\"url\":\"https://github.com/coder/coder/releases/tag/v2.34.2\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Release Notes\"]},{\"url\":\"https://github.com/coder/coder/security/advisories/GHSA-wrq8-fcv5-8hvp\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Patch\",\"Vendor Advisory\"]}]}}",
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-55428\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"total\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-07-08T13:10:59.507766Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-07-08T13:11:04.149Z\"}}], \"cna\": {\"title\": \"Coder: Route hijacking through lack of validation of agent-supplied AllowedIPs in tailnet coordinator\", \"source\": {\"advisory\": \"GHSA-wrq8-fcv5-8hvp\", \"discovery\": \"UNKNOWN\"}, \"metrics\": [{\"cvssV3_1\": {\"scope\": \"CHANGED\", \"version\": \"3.1\", \"baseScore\": 8.2, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N\", \"integrityImpact\": \"HIGH\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"HIGH\", \"availabilityImpact\": \"NONE\", \"privilegesRequired\": \"LOW\", \"confidentialityImpact\": \"HIGH\"}}], \"affected\": [{\"vendor\": \"coder\", \"product\": \"coder\", \"versions\": [{\"status\": \"affected\", \"version\": \"\u003e= 2.34.0, \u003c 2.34.2\"}, {\"status\": \"affected\", \"version\": \"\u003e= 2.33.0, \u003c 2.33.8\"}, {\"status\": \"affected\", \"version\": \"\u003e= 2.30.0, \u003c 2.32.7\"}, {\"status\": \"affected\", \"version\": \"\u003c 2.29.17\"}]}], \"references\": [{\"url\": \"https://github.com/coder/coder/security/advisories/GHSA-wrq8-fcv5-8hvp\", \"name\": \"https://github.com/coder/coder/security/advisories/GHSA-wrq8-fcv5-8hvp\", \"tags\": [\"x_refsource_CONFIRM\"]}, {\"url\": \"https://github.com/coder/coder/pull/26144\", \"name\": \"https://github.com/coder/coder/pull/26144\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://github.com/coder/coder/releases/tag/v2.29.17\", \"name\": \"https://github.com/coder/coder/releases/tag/v2.29.17\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://github.com/coder/coder/releases/tag/v2.32.7\", \"name\": \"https://github.com/coder/coder/releases/tag/v2.32.7\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://github.com/coder/coder/releases/tag/v2.33.8\", \"name\": \"https://github.com/coder/coder/releases/tag/v2.33.8\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://github.com/coder/coder/releases/tag/v2.34.2\", \"name\": \"https://github.com/coder/coder/releases/tag/v2.34.2\", \"tags\": [\"x_refsource_MISC\"]}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"Coder allows organizations to provision remote development environments via Terraform. Prior to versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2, the tailnet coordinator validates that an agent\u0027s `Addresses` derive from its authenticated UUID but applies no equivalent check to `AllowedIPs`. The coordinator forwards agent-supplied `AllowedIPs` verbatim to tunnel peers which install them into the WireGuard peer configuration. The fix in versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2 validates each `AllowedIPs` prefix against the authenticating agent\u0027s UUID just like `Addresses`. As a workaround, monitor coordinator logs for agents advertising unexpected `AllowedIPs` prefixes.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-285\", \"description\": \"CWE-285: Improper Authorization\"}]}, {\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-863\", \"description\": \"CWE-863: Incorrect Authorization\"}]}], \"providerMetadata\": {\"orgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"shortName\": \"GitHub_M\", \"dateUpdated\": \"2026-07-07T23:57:45.338Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-55428\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-07-08T13:11:08.435Z\", \"dateReserved\": \"2026-06-16T21:59:57.016Z\", \"assignerOrgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"datePublished\": \"2026-07-07T23:57:45.338Z\", \"assignerShortName\": \"GitHub_M\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.